GRIP RoboRIO Class List - PatrickPenguinTurtle/GRIPWiki GitHub Wiki
If you're developing for GRIP on the RoboRIO, you will have to take special consideration into what imports you do and don't use. The RoboRIO uses an embedded version of the Java Runtime, meaning some desktop packages (such as java.awt) will not be present. If you're looking to contribute to GRIP, make sure that any JDK classes you use are available on the RoboRIO. As a general rule of thumb, if it's under java.awt, it won't be present and therefore it won't run on the RoboRIO. If you're not sure, grab a RoboRIO and test it.
If you want some piece of mind, here's a gist generated by Jaci that contains every single class available on the RoboRIO's 2015/2016 JDK. Keep in mind, it follows the convention of some/java/package/MyClass.class, or some/java/package/MyClass$InnerClass.class for nested classes. (Warning, this file is over 7000 lines long, don't view on mobile)